The cacique is gregarious, and is generally found in large flocks,-- sometimes one species building their nests on one side of a tree, while another, with a neighbourly feeling, appears to have selected the opposite side; and they may be seen working amicably away, without interfering with each other. They show wonderful instinct in the selection of trees, sometimes hanging their large pendulous nests to the extremities of palm branches, that they may thus be as much as possible out of the reach of enemies who might attempt to take their young brood. Others are said to select the trees on which the stinging-wasps have already built their nests, as no tiger-cat nor reptile of any description would venture to attack such adversaries. One species (the casicus cristatus) weaves its nest of lichens, bark fibres, and the filaments of the tillandsias; another (the casicus ruba) of dry grasses, and always suspends it over the water. This has a slanting opening in the side, so that no rain can penetrate it. TOUCANS. During the dry season, on the topmost boughs of the lofty trees growing on the gapo lands, large gaily-coloured birds, with huge beaks of the shape of a banana or pacova, are perched, in bands of five or six, uttering loud, shrill, and yelping cries, having somewhat the resemblance to "Tocano! tocano! tocano!" Hence the Indians give them the name from which we derive _toucan_--a bird especially characteristic of the forests of Tropical America. The Brazilians also call them "preacher-birds,"--from their habit of lifting up their beaks, and clattering them together, and shouting hoarsely. One, mounted higher than the rest, acts either as the leader of the inharmonious chorus, or does the duty of sentinel. He keeps a bright look-out on every side, and as danger approaches, gives a warning cry, when his companions stretch their necks downwards in an inquisitive manner, to ascertain what foe is below; and on espying the least movement among the foliage, fly off to a distance. Sometimes the whole flock, including the sentinel, set up simultaneously a deafening loud yell, which can be heard a mile off, and serves to lead the hunter to their haunts. They are said also to mob any strange bird which gets among them, surrounding it, and shrieking at it in whichever way it turns; so that it sees itself surrounded on all sides by huge snapping bills, and long tails bobbing regularly up and down with threatening gestures, till it is seized by its foes or manages to make its escape.